A certain radioactive element has a half-life of one hour. if you start with 1.0 gram of the element at noon, how much of the radioactive element will be left at 2 p. m.? 0.50 grams 0.25 grams 0.125 grams 0.0 grams

Match the atomic particles with their electrical charges. 1. positive (+) electron 2. negative (-) proton 3. neutral (0) neutron

Basic substances have a gritty texture. TRUE FALSE A substance is added to pure water and the concentration of aqueous H + ions increases. What kind of substance has been added to the water? an acid a base water either an acid or a base

Kinetics of chymotrypsin shows a biphasic pattern; the burst phase and the steady-state phase. 一一 (T/F)

Which of the following best represents and explains the formula for a compound made from fluorine and hydrogen? HF, because both fluorine and hydrogen are capable of forming only one ionic bond.

When the equation below is completely balanced, what will be the coefficient for Fe2O3?

The SI unit for current is: joules volts ohms amps

In chemical reactions, there is a conservation of what?

If the temperature of water increases as you heat it, the temperature is the independent variable. True False

Which is made by weathering? A. sediments B. minerals C. ash D. magma

Which Of These Is An Indication That A Chemical Reaction Has Occurred? A. Freezing Of A Substance B. Melting Of A Substance C. Boiling Of A Substance D. Formation Of A Gas